Applying with precision

Returns from sheep and cattle farming of New Zealand’s hill country are increasingly marginal, so the government is looking to precision or satellite agriculture to boost productivity and revenue.

Professor Ian Yule and Senior Lecturer Miles Grafton are part of Massey’s New Zealand Centre for Precision Agriculture, which creates practical land-management solutions through the use of leading-edge precision technology tools to observe, measure and respond to inter- and intra-field variability in pasture and crops.

With partner AgResearch, the centre is part of the Pioneering to Precision programme led by Ravensdown and funded by the Ministry for Primary Industries (MPI), which seeks to improve fertiliser practice on hill-country farms through remote sensing of their nutrient status and the precision application of fertiliser.

Currently, fertiliser is applied to hill-country farms using topdressing aircraft which broadcast the fertiliser in blanket applications, based on the assumption that the nutrient status of the land is relatively uniform. This results in over-fertilising and wastage in some areas, and under-fertilising and poor growth in others. On top of that are topdressing fees, increasing environmental regulations and manual soil-testing on foot, all of which make fertiliser application expensive and problematic.

Precision application technology uses remote sensing of the nutrient status of the land to determine where nutrients should be targeted. GPS-guided aircraft then deliver fertiliser to the specified areas. The technology also enables farmers to minimise the discharge of nutrients into waterways.

Images from 450 wave-bands

Professor Ian Yule and Senior Lecturer Miles Grafton
The Massey researchers use the latest imaging tool for aerial scanning of farms and testing soil nutrients from the air. A $500,000 Fenix hyper-spectral imaging system (from Finnish company Specim) is installed on an aircraft and flown over land to gather images from more than 450 wave-bands including visible, near, short and infra-red. Maps are then developed showing pasture quality, nutrient content and concentration. The imaging system can also be calibrated to show diseased plants and individual species of plants and trees.

Ravensdown has developed a model to predict where aerially applied fertiliser will land, which takes into account the flow rate (how much fertiliser is coming out of the plane), aircraft speed, wind speed and the width the fertiliser is spread over.

Eight farms in Waikato, Whanganui, Rangitikei, Wairarapa, Nelson, Canterbury and Otago are being used for the research, and to date more than 9500 soil and plant tissue samples have been collected, representing the most comprehensive nutrient requirement dataset in New Zealand.

The research gives hill-country farmers the opportunity to understand and manage their farms’ soil fertility to potentially raise herbage quantity and quality, prevent erosion and improve seasonality of feed supply, while reducing workload.

“The primary growth partnership project has acted as a catalyst and allowed us to make a technological leap in terms of the way we describe our environment,” Professor Yule says.

If successful, this programme will transform the way fertiliser is applied in farming in New Zealand.

By 2024 it’s anticipated the precision fertiliser application system will be increasingly adopted by New Zealand’s hill-country farmers. MPI estimates the Pioneering to Precision programme will improve the profitability of hill-country farming and generate earnings of $120 million a year by 2030 from additional exports of meat and wool.

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Last updated on Friday 28 October 2016

"The primary growth partnership project has acted as a catalyst and allowed us to make a technological leap in terms of the way we describe our environment."